Transfusion monitoring device



2083 REFERENCE m 2,807 013 SEARCH RUUM Sept. 17, 1957 2,807,012

H. SCHWARZ TRANSFUSION MONITORING DEVICE Filed June 8, 1953 AMPLIFIER fihbeflt 6 0726065716 2807012 2 OR IN 340/23?? United States Patent '9 M TRANSFUSION MONITORING DEVICE Herbert Schwarz, Woodrolfe, Ontario, Canada Application June 8, 1953, Serial No. 360,140

3 Claims. (Cl. 340-239) This invention relates to a device for monitoring transfusions given to a patient, and other surgical procedures carried out in a similar manner. The invention described herein is not however restricted in its use to surgical applications, but is capable of wider use in industrial techniques where it is desired to monitor the flow of fluids.

In some transfusions, time is not important, and the liquid is allowed to flow to the patient at any convenient rate, but in other transfusions timing is very important, and it is to the latter class of cases that this invention is particularly directed. Specifically the present invention is particularly useful in detecting any sudden changes in the rate of flow to a patient, such as might be caused by the transfusion device suddenly getting out of adjustment.

Heretofore it has been the practice during transfusions to have a nurse inspect the various patients from time to time, to determine whether the flow is proceeding at the proper rate, by counting drops in a visible portion of the apparatus for a short interval of time.

Such a method is exceedingly disadvantageous because of the great amount of supervsion required.

It is a principal object of this invention to overcome the principal disadvantages referred to above by providing a device which requires a minimum of supervision.

It is a further object to provide a device which is convenient for use in hospitals and is particularly advantageous from the standpoint of sterilization because of its separable structure wherein the parts requiring sterilization are easily separated from those not requiring to be sterilized.

An additional object is to provide a device constructed of parts which are easily obtainable and low in cost.

A further object of this invention is to provide a device wherein the flow of liquid to the patient may be observed or otherwise indicated at a distance remote from the patient without the necessity of any complicated apparatus.

It is also an object to provide for a plurality of transfusions to be monitored simultaneously by a single nurse or orderly, with the assistance of the device described herein.

Other objects of the present invention will be apparent to one skilled in the art from an examination of the present specification and the accompanying drawings.

A preferred embodiment of the invention may consist briefly of a means for allowing the blood or other liquid to fall in the form of drops as it passes to the patient, and in combination therewith, a sound-sensing means whereby the sound of such drops falling may be remotely observed, through suitable amplifying and indication means.

In the accompanying drawing wherein like parts are denoted by identical reference numerals,

Figure 1 shows a general view of a preferred form of the device in use; and

Figure 2 shows an enlarged fragmentary cross-sectional 2,807,012 Patented Sept. 17, 1957 view of the device with the electrical parts shown schematically.

It will be appreciated that modifications are possible without departing from the scope of the invention.

In the accompanying drawing a supply bottle is shown at 1 from which blood or other liquid flows to the patient. Supply bottle 1 is connected by tube 2 to tube 3 whence connection is made to the patient.

Tube 3 has an enlarged portion shown at 4, and within the latter there is provided a nozzle shown at 5. A tap 6 controls the flow to nozzle 5. It is apparent from the accompanying drawing that tap 6 may be adjusted so that the liquid in question may be caused to fall in drops in the enlarged portion 4 of tube 3. Such drops are denoted by 8.

As the drops 8 fall, they produce minute splashes which, While inaudible to the human car, may be sensed by means of a microphone. For this latter purpose, a microphone shown at 9 is accordingly attached to enlarged portion 4 of tube 3 in any suitable manner. It is not considered desirable that microphone 9 be made integral with enlarged portion 4 because of the difliculties of sterilizing such a composite device, but the invention is in no way limited to such attachable construction. It is also contemplated that the microphone may be attached to the enlarged portion 4 by means of a soundtransmitting tube, in the manner of a stethoscope.

In addition to its use for the purpose described, the microphone 9 may be used by the patient to communicate vocally through the loudspeaker referred to below.

Microphone 9 is connected to amplifier 10 by means of a suitable connection which is indicated by 11. A loudspeaker shown at 12 could be attached to amplifier 10 by means of a suitable connection shown at 13.

It should be understood that the transfusion invention is not limited to the use of a loud speaker or any sound producing means, and, for example a light could be easily provided instead of loud speaker 12, the flashes of which light would indicate the falling of drops in enlarged por-' tion 4.

Another indicating means which can be used is a counter, which is shown at 14, capable of being attached to amplifier 10 by means of connection 15.

When a counter is used, the sound impulses picked up by microphone 9 may be converted into electrical impulses which in turn move a suitable hand to indicate the number of drops falling during a given period.

It is also contemplated that a rate of flow indicator could be provided as will be understood by one skilled in the art.

It will be realized that the invention herein disclosed provides a simpler and more effective technique than found in the prior art, and has numerous advantages in the economy of construction and the reliability of the apparatus, which will be a considerable aid in surgery.

I claim:

1. A transfusion monitoring device for monitoring the flow of liquid drops comprising a splash chamber, a microphone attached to said splash chamber capable of sensing splashes occuring in said splash chamber due to said liquid drops, an amplifier connected to said microphone and indicating means connected to said amplifier whereby the indicating means is indicative of the presence or absence of the flow of liquid drops within said chamber. 2. A transfusion monitoring device for monitoring the flow of liquid drops comprising a splash chamber, a microphone in close proximity to said splash chamber capable of sensing splashes in said splash chamber due to said liquid drops, an amplifier connected to said microphone and indicating means connected to said amplifier whereby the indicating means is indicative of the presence or absence of the flow of liquid drops within said chamber.

3. A transfusion monitoring device for monitoring the flow of liquid drops comprising a splash chamber, indicating means, means for sensing sound impulses occuring in said splash chamber and occuring in response to the flow of liquid drops therein, and means for applying signals generated by said sensing means to said indicating means, whereby the indicating means is indicative of the presence or absence of the flow of liquid drops within said chamber.

References Cited in the file of this patent UNITED STATES PATENTS Harris May 21, 1935 Hardinge Mar. 25, 1941 Greacen, et a1. Jan. 4, 1955 FOREIGN PATENTS Switzerland Oct. 1, 1938 Germany Feb. 18, 1925 

